Advises on training plan to a 1 hour best effort

Hello everyone,

Male 30, 4.0 FTP (280), 400 hours on the bike since 1.5 years, looking to increase to 300W but struggling.

I would like to orientate my training plan in order to be able to maintain the highest possible average power over 1 hour.

I intend to organize my training plan around the themes of “polarized training” and “progressive overload”, organized in 4-week cycles.

Cycle 1:
Week 1 to week 3: steady increase of volume and intensity
Week 4: recovery.

Cycle 2 :
Week 5 to 8: steady increase of voulme and intensity, starting at a slightly higher level from cycle 1.
Week 8: recuperation.

Cycle 3 :

As i already run (<2hours), swim(<4hours), and am pretty time crunched, i can’t really do more than 8 hours of biking per week.

I plan to do 2x 1 hours of HIT training, remainder being at zone 2.

Questions about HIT sessions :

What is better, do always the same kind of HIT sessions ?
Alternate between 2 HIT sessions ?
After how long should i change the intervals ?
As i want to perform over a 1 hour hold, i guess i will have to train at FTP (2x20…). As those training are pretty tough, could they replace a HIT session ?

Bonus question about Z2,

What is better, do 2x1 hours at zone 2 on 2 different days, or a single 2 hours sessions ?

Thanks you for your help.

One 2hr z2 is better than two 1hr.

I’d train tempo → SS → threshold and not bother with intensities beyond that.

I’d also swim and run less to bike more.

Lastly, ride 280 for 1hr first before you plan to PR and do 300 if your 280 number comes from a ramp or 20min test. I just hit a big PR on a 20min test and I am not confident I could ride 95% of that power for 60min without specific training to do so

I’d start with doing progressively longer intervals at 85% or 90% of FTP. Do 3x20, 2x30, 1x45 and then 1x60. Once you get "comfortable doing 60 minutes, then you can increase the %. Personally, I’d go past 60 minutes at the lower intensities before I’d ramp up the intensity at 60 minutes, but that just suits me on longer rides. I’m not so concerned about my FTP.